Protective screen arrangement for an agricultural machine

ABSTRACT

An agricultural machine is described with a screen for protecting a part of a cooling system of a motor mounted on the agricultural machine, the screen being mounted in its operational position adjacent the cooling system, wherein the screen is movable from the operational position next to the cooling system of the motor to a position in which the screen lies outside the envelope defining the outer form of the agricultural machine, the screen being hingedly connected to the agricultural machine so that the initial trajectory of the screen is horizontal and substantially perpendicular to the longitudinal axis of the agricultural machine, and that a further second trajectory of the screen is horizontal and substantially circular, having its centre of curvature on or adjacent a first hinge position.

TECHNICAL FIELD

The present invention relates generally to self-propelled agriculturalmachinery such as forage harvesters, having a drive motor and aprotective screen in front of an air intake of the cooling system of themotor, e.g. for a cooling fan and/or a radiator.

TECHNICAL BACKGROUND

A self-propelled agricultural machine typically has a drive motor fordriving the machine and for operating one or more functional units, e.g.cutterhead, crop processors, blowers. The motor is usually an internalcombustion engine, e.g. a diesel motor, which has a cooling systemincluding a radiator and often a fan for drawing in or blowing airthrough the radiator. Such agricultural machines are subject to largeamounts of dust, dry leaves and other crop materials which are thrown uparound the machine as it progresses across the field. In additioninsects may be disturbed by the machine and be drawn towards the airinlet for the cooling system of the motor. To prevent such materials andobjects from blocking the radiator, a protective screen is placed infront of the radiator and/or fan. Protective screens are often rotatedpast a solid plate in order to facilitate removal of accumulatedmaterial from the outer screen surface.

DE-A-195 47 348 shows a forage harvester comprising a motor or enginemounted to the rear of the machine. The protective screen and theradiator have an asymmetric position in the vehicle along the sideshielding of the harvester. Access to components behind the screen iseasily obtained by swinging the screen outwardly about a vertical axis.However, the position of the filled radiator and the screen cause adisadvantageous distribution of the weight of the vehicle.

For an in-line arrangement of an agricultural machine as shownschematically in FIG. 1, a diesel motor 60 may located behind anagricultural functional unit located beneath the cab 22. The main driveshaft of the motor is parallel with the longitudinal axis of themachine. The machine has a frame 1 to which major items are anchored.The motor 60 has a radiator 64, a cooling fan 62 and a rotating screen68 all in line with the front-rear axis of the machine. Typically, theradiator 64, cooling fan 62 and the rotating screen 68 (in total acooling block) are mounted between the motor 60 and the cab 22. Thisplaces the motor 60 at the most rearward part of the machine whichprovides a counterweight to the weight of the functional units at thefront, for instance it avoids or reduces the use of counterweights atthe back of the machine. Although weight distribution on the machine issolved in this way, it results in the cooling block being locatedbetween the motor 60 and the cab 22. In order to allow access to thescreen 68 and to remove this for servicing of the radiator 64 and/or thefunctional units it is conceivable to allow a space 70 in front ofscreen 68. This space 70, however, increases the overall length of themachine so that it is preferred if this space 70 can be reduced to aminimum. As the screen 68 comes closer to the cab 22, the chance ofinterference with other components such as the tires of the front wheels2 increases when the screen is pivoted away from the radiator. Further,providing adequate access to the cooling system and/or the functionalunits becomes more difficult.

One advantage of the in-line motor arrangement is that the cooling airflow from the fan 62 can be directed onto and along both sides and thetop of the motor 60 thus reducing the chances of accumulation of drycrop material or leaves on exposed hot spots on the motor 60 which couldreach such a temperature that dry crop material or leaves are setalight.

It is an objective of the present invention to provide a betterarrangement for moving the screen in order to gain access to the coolingsystem and/or other functional units of an agricultural machine.

SUMMARY OF THE INVENTION

The present invention provides an agricultural machine with a screen forprotecting a part of a cooling system of a motor mounted on theagricultural machine, the screen being mounted in its operationalposition substantially perpendicular to the longitudinal axis of themachine and adjacent the cooling system wherein the screen is movablefrom the operational position next to the cooling system of the motor toa position in which the screen lies outside the envelope defining theouter form of the agricultural machine, characterised in that the screenis being hingedly connected to the agricultural machine so that theinitial trajectory of the screen is horizontal and substantiallyperpendicular to the longitudinal axis of the agricultural machine, andthat a further second trajectory of the screen is horizontal andsubstantially circular, having its centre of curvature on or adjacent afirst hinge position.

The first trajectory may be substantially translational, i.e. with no orlittle rotation of the screen with respect to the machine. The screen ispreferably supported-during its trajectory by an elongate support memberor frame, the support member being hingedly connected to theagricultural machine at one end of the member by a first vertical hingeat the first hinge position and the screen is hingedly connected to oneother end of the support member via a second vertical hinge between thescreen and the member at a second hinge a position. The second hingeposition is preferably offset from the centre of the screen so that thescreen can swing out like a door in an optional third trajectory thusleaving even more space for access to the cooling system. The firsthinge position is preferably in front of or behind the operationalscreen position with reference to the longitudinal axis of the machine.Preferably the screen has an air inlet direction which is parallel tothe longitudinal axis of the machine and the screen mesh is supported bya plate or frame which lies in a plane perpendicular to the longitudinalaxis. Preferably, the first hinge position lies close to a line parallelto the longitudinal axis of the machine which passes through one lateralextremity of the screen support plate or frame. A line joining the firsthinge position to the extremity preferably makes an acute angle,preferably an angle of 10° or less, to the longitudinal axis of themachine. The first hinge position preferably lies closer to the centrallongitudinal axis of the machine than the screen support plate or frameextremity. Preferably, the motor, a part of the cooling system and thescreen are arranged along the longitudinal axis of the machine.Typically, the part of the cooling system will be a radiator. A fan maybe mounted in-line with respect to the motor, the part of the coolingsystem and the screen.

The dependent claims define further individual embodiments of thepresent invention. An agricultural machine and a method of its operationin accordance with the present invention will now be described ingreater detail, by way of example, with reference to the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side elevational view of an agricultural machinewith which the present invention may be used.

FIG. 2 is a schematic top view of the agricultural machine of FIG. 1showing the first to third trajectories of a protective screen inaccordance with an embodiment of the present invention.

FIG. 3 is a schematic top view of a detail of a support member and guiderod assembly in accordance with an embodiment of the present invention.

FIG. 4 is a schematic top view of the detail of the support member andguide rod assembly shown in FIG. 3 showing the operational position andan opened position of the protective screen.

FIG. 5 is a schematic representation of the first and secondtrajectories of the assembly shown in FIG. 3.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

The present invention will be described with reference to certainembodiments and certain drawings but the invention is not limitedthereto but only by the claims. The drawings are schematic. The terms“front”, “rear”, “forward”, “rearward”, “right” and “left” usedthroughout the specification are determined with respect to the normaldirection of movement of the machine in operation and are not to beconstrued as limiting terms.

With reference to the drawings and more particularly to FIG. 1, there isshown an agricultural machine, e.g. a forage harvester, having a mainframe 1 on which are mounted ground engaging traction wheels 2 andsteering wheels 3. The forage harvester is shown equipped with a cropcollecting apparatus, in the form of a row crop attachment 10, suitablefor the harvesting of maize, but which can be replaced with aconventional windrow pick-up device or a conventional cutter barattachment, depending on the type of crop to be harvested. Customarily,the row crop attachment 10 comprises an attachment frame 12, whichsupports a plurality of row crop units 14, operable to harvest maizestalks from the field and to convey the same rearwardly to an auger 16,which in turn delivers the crop material to the bite of feeder meansinstalled in a front unit of the forage harvester.

The forage harvester has feeding means which comprise lower feedermeans, including a forward lower feed roll 26, and a smooth, rear lowerfeed roll 27, and upper feeder means, including an upper forward feedroll 20 and an upper rear feed roll 21. The lower feed rolls 26, 27 arerotatably mounted in a lower feeder frame 24 and the upper feed rolls20, 21 are mounted in an upper feeder frame 18, to which the row cropattachment 10 is attached. The upper and lower feeder means rotate toconvey the crop material in-between to a cutter-head 36, which comprisesa plurality of knives 37, generating a cylindrical peripheral shape orprofile, when the cutter-head 36 is rotated.

The knives 37 co-operate with a fixed shearbar to cut the crop materialto length. A crop processor roll assembly 42 is provided comprising aset of counter-rotating compressor rolls 44 mounted therein, which rollscrack the kernels which are left in the chopped material. The compressorrolls 44 may have a substantially cylindrical, fluted surface. Thecutter-head 36 projects the cut material into the bite of the compressorroll assembly 42. This delivers the crushed maize kernels to a blower 50which is installed within a blower housing 48. The blower 50 comprises aplurality of paddles, which throw the material upwardly through theblower or accelerator outlet into a discharge spout 52, which can bepositioned by an operator to direct the cut crop material as required,normally into a wagon which is moving alongside or behind the forageharvester.

FIG. 2 is a schematic top view of the agricultural machine of FIG. 1. Amotor 60, e.g. a diesel engine, is mounted between the rear wheels 3. Aradiator 64 is located in-line with the motor 60 as well as a fanmounted in a fan housing 62 for drawing air through the radiator 64. Infront of the radiator, a dust screen, preferably a rotating screen 68 ismounted in such a way that it can swing out along a first trajectory 77followed by a second trajectory 78 and an optional third trajectory 79.Trajectory 77 is characterised by an initial section starting from thenormally operational position of screen 68 when it is directly in frontof radiator 64, the initial section consisting substantially of atranslational movement substantially perpendicular to the longitudinalaxis of the agricultural machine. In a middle portion, the furthertrajectory 78 of screen 68 rotates through an angle to a point where itis has turned through an angle of about 60 to 90° from its operationalposition. From this point on a third optional trajectory 79 can be usedwhich is mainly a rotation about a hinge 76 until the screen 68 hasmoved an angular distance of between 135 and 180° compared with itsstarting position.

An advantage of the initial substantially translational motion of thescreen 68 in trajectory 77 is that the space 70 in front of the screen68 can be kept to a minimum. Also, the movement of the screen 68 doesnot interfere with the tire of front wheel 2. However, once trajectory77 is completed, trajectories 78 and 79 take the screen 68 completelyaway from the space 70 and outside the envelope defined by the outsidecontours of the machine thus allowing access from both sides of themachine.

To achieve the three trajectories 77 to 79 one embodiment of the presentinvention will now be described. Typically, the screen 68 will bemounted on a support 69, e.g. a frame or plate. The screen 68 isrotatably connected to a part of the frame 1, or a subframe or otherstructural component connected to the frame 1 at a first hinge position75 via a support member 74. The screen 68 is also rotatably connected tothe member 74 at a second hinge position 76 which may be on the support69. Preferably two members 74 are used, one at or near the top and oneat or near the bottom of the screen 68. The double hinge attachment (75,76) of the screen 68 allows the screen 68 to follow the trajectories77–79. Preferably, the one or more elongate support members 74 areattached at one end to a position either axially behind or in front ofthe screen 68 so that the initial motion is the tangent to a circlewhose centre lies either axially in front or behind the screen 68.Preferably, the centre of the circle, i.e. the first hinge position 75is placed so that the initial motion of screen 68 is substantiallyperpendicular to the longitudinal axis of the agricultural machine. Thesecond hinge position 76 is preferably placed towards a side of thescreen 68 (i.e. offset from the centre of the screen 68) so thatrotation about this hinge 76 swings the screen 68 away from theagricultural machine like a door and not simply about its own axis.Member 74 may be straight or may advantageously have a first bend 80 toclear the radiator 64 when the screen 68 is in the operational position.Member 74 may be composed of individual struts or be part of a frame.

In a preferred embodiment the member 74 has a generally hook shape witha first bend 80, straight shank portion 72 and a hook portion 73defining a space 71 as shown best in FIG. 3. The extreme end of the hookportion 73 is connected to the hinge at the second hinge position 76.The screen 68 is mounted on support 69 so that there are portions 69Aand B of the support 69 which extend beyond the outer edge of the screen68. The second hinge position 76 is located closer to the centre of thescreen than the outer edge of support 68 so that the angle α between theline connecting hinge positions 75, 76 and the normal to support 69 ofscreen 68 is acute, e.g. 30° or less, more preferably 20° or less. Thefirst hinge position 75 may be located so that the angle between thefirst hinge position 75 and an extreme edge 81 of the support 69 makesan acute angle β with respect to a normal to the support 69, This angleβ is preferably smaller than a and is preferably in the range 0 to 100.The first hinge 75 is placed closer to the central longitudinal axis ofthe machine than the extreme edge of the support 69. The angle α may notbe too large otherwise the screen 68 moves too far away from theradiator 64 during the first trajectory 77 thus requiring more forwardspace 70. As the trajectory 77 continues the edge 81 of support 69 tucksinto the hook region 71 thus allowing the screen 68 to remainsubstantially perpendicular to the longitudinal axis of the machine,i.e. not to rotate about the hinge position 76 initially, In this waythe initial trajectory 77 of the screen is substantially perpendicularto the longitudinal axis of the machine. In the further trajectory 78the screen 68 mainly rotates about the first hinge position 75, i.e. ina substantially circular manner. At the end of the second trajectory 78,the screen 68 may be rotated only around hinge position 76, i.e.swinging screen 68 like a door, in a third trajectory 79.

The screen 68 may be guided along the trajectory 77 by hand. However, inaccordance with another, preferred embodiment of the present invention aguide member may be used to positively control the movement of screen68. Such a guide member may be a guide rod 84 as shown in FIGS. 3 to 5.The rear end of rod 84 is hingedly connected at a position 86 to theframe 1 near the hinge position 75 but located further away from thecentral longitudinal axis of the machine. The front end of rod 84 ishingedly connected at position 87 to the front face of support 69. Therod 84 has a bend 89 to provide room for the edge 81 of the radiatorhousing. The angle γ between the normal to the screen support 69 and theline connecting hinge positions 86, 87 is preferably acute, preferablysmaller than the angle α. This arrangement forms a parallelogram-typelinkage formed by the member 74, the rod 84 and portions of frame 1 andsupport 69 between the hinge positions 75, 86 and 76, 87 respectively.Such a linkage effects a substantially parallel movement of the supportmember 74 and the rod 84 during the initial phase of trajectory 77.Preferably, the front hinge position 87 of the guide rod 84 liesforwards of the first second hinge position 76 of the support member 74,i.e. the hinge position is located further away along a normal tosupport 69 with reference to the hinge position 86 than the hingeposition 76. To achieve this hinge position 87 may be located on a boss85 attached to the front face of support 69. The discrepancy ineffective length of member 74 and rod 84 induces a substantiallycircular movement of screen 68 during the further trajectory 78. Thecomplete trajectory is shown schematically in FIG. 5. Due to is theguide rod 84 the final trajectory 79 is prevented. However, as anadditional option, the rod 84 could be decoupled from one of the hingepositions 86, 87 or separated in the middle thereof and then the screen68 swung about hinge position 76 like a door.

While the invention has been shown and described with reference topreferred embodiments, it will be understood by those skilled in the artthat various changes or modifications in form and detail may be madewithout departing from the scope and spirit of this invention as definedby the claims. For instance, member 74 need not be of fixed length, itcould also be provided with a hydraulic cylinder so that its length canbe varied.

1. An agricultural machine with a screen for protecting a part of acooling system of a motor mounted on the agricultural machine, thescreen being mounted in its operational position substantiallyperpendicular to the longitudinal axis of the machine and adjacent thecooling system wherein the screen is movable from the operationalposition next to the cooling system of the motor to a position in whichthe screen lies outside the envelope defining the outer form of theagricultural machine, wherein said screen is hingedly connected to theagricultural machine so that the initial trajectory of the screen ishorizontal and substantially perpendicular to the longitudinal axis ofthe agricultural machine, and that a further second trajectory of thescreen is horizontal and substantially circular, having its centre ofcurvature on or adjacent a first hinge position, further comprising anelongate support member, the support member being hingedly connected tothe agricultural machine at one end of the member by a first verticalhinge at the first hinge position and the screen is hingedly connectedto one other end of the support member via a second vertical hingebetween the screen and the member at a second hinge position, whereinthe second hinge position is offset from the centre of the screen, thefirst hinge position is in front of or behind the operational screenposition with reference to the longitudinal axis of the machine, themotor, a part of the cooling system and the screen are arranged alongthe longitudinal axis of the machine and part of the cooling system is aradiator, further comprising a fan mounted in-line with respect to themotor, the part of the cooling system and the screen and furthercomprising a guide member, the guide member being hingedly connected tothe agricultural machine at one end of the member by a third verticalhinge at a third hinge position and the screen is hingedly connected toone other end of the guide member via a fourth vertical hinge at afourth hinge position, the lines joining the first and second hingepositions and the third and fourth hinge positions being substantiallyparallel when the screen is in its operational position.
 2. The machineaccording to claim 1, wherein the third hinge position is locatedfarther away from the central axis of the machine than the first hingeposition, and the fourth hinge position is located further away from thecentre of the screen than the second hinge position.
 3. The machineaccording to claim 2, wherein the effective length of the guide memberis longer than the effective length of the support member.
 4. Themachine according to 3, further comprising a first angle (α) between theline joining the first and second hinge positions and the longitudinalaxis of the machine is acute, less than 30° when the screen is in theoperational position.
 5. The machine according to claim 4, furthercomprising a second angle (γ) between the line joining the third andfourth hinge positions and the longitudinal axis of the machine isacute, preferably less than the first angle (α).
 6. The machineaccording to claim 5, further comprising a third angle (β) between theline joining the first hinge position and a terminating edge of thescreen which is remote from the centre line of the machine in ahorizontal direction is less than the first angle (α).
 7. The machineaccording to claim 6, characterised in that the screen and supportmember or adapted to allow a third trajectory after the secondtrajectory, the third trajectory being a rotation of the screen aboutthe second hinge.
 8. The machine according to 4, further comprising afirst angle (a) between the line joining the first and second hingepositions and the longitudinal axis of the machine is acute, less than20′ when the screen is in the operational position.